diff --git a/src/slurmd/slurmstepd/Makefile.am b/src/slurmd/slurmstepd/Makefile.am
index 35087730f683fe8eef9f0ec80ddf290eaa5c1038..0e59bab3a1874149c565660c7fe0b82abe3c7b81 100644
--- a/src/slurmd/slurmstepd/Makefile.am
+++ b/src/slurmd/slurmstepd/Makefile.am
@@ -25,6 +25,7 @@ slurmstepd_SOURCES = \
ulimits.c ulimits.h \
pdebug.c pdebug.h \
req.c req.h \
+ task_exec.c task_exec.h \
$(top_builddir)/src/slurmd/common/proctrack.c \
$(top_builddir)/src/slurmd/common/proctrack.h \
$(top_builddir)/src/slurmd/common/setproctitle.c \
diff --git a/src/slurmd/slurmstepd/task_exec.c b/src/slurmd/slurmstepd/task_exec.c
new file mode 100644
index 0000000000000000000000000000000000000000..122afebaa1521e11807997ca01dc6f05dc539aa5
--- /dev/null
+++ b/src/slurmd/slurmstepd/task_exec.c
@@ -0,0 +1,341 @@
+/*****************************************************************************\
+ * task_exec.c - execute program according to task rank
+ *
+ * NOTE: This code could be moved to srun if desired. That would mean the
+ * logic would be executed once per job instead of once per task. It would
+ * also eliminate the need for the configurate file on every compute node.
+ * This would also permit running a debugger on a heterogeneous collection
+ * of programs (if it can handle this).
+ * Doing so would necessite modifying the task launch RPC to send not one
+ * executable name and argument list, but a set of them.
+ *****************************************************************************
+ * Produced at National University of Defense Technology (China)
+ * Written by Hongjia Cao <hjcao@nudt.edu.cn>
+ * and
+ * Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ * Written by Morris Jette <jette1@llnl.gov>.
+ * UCRL-CODE-217948.
+ *
+ * This file is part of SLURM, a resource management program.
+ * For details, see <http://www.llnl.gov/linux/slurm/>.
+ *
+ * SLURM is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * SLURM is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with SLURM; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+\*****************************************************************************/
+
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "src/common/log.h"
+#include "src/common/xassert.h"
+#include "src/common/xmalloc.h"
+#include "src/common/xstring.h"
+
+#define BUF_SIZE 256
+
+/*
+ * Test if the specified rank is included in the supplied task range
+ * IN rank - this task's rank
+ * IN spec - a line from the configuration file
+ * OUT offset - the task's offset within rank range of the configuration file
+ * RET 1 if within range, 0 otherwise
+ */
+static int
+_in_range(int rank, char* spec, int *offset)
+{
+ char* range;
+ char* p;
+ char* upper;
+ int high_num, low_num, passed = 0;
+
+ xassert(offset);
+
+ if (spec[0] == '*' && spec[1] == '\0') {
+ *offset = rank;
+ return 1;
+ }
+
+ for (range = strtok (spec, ","); range != NULL;
+ range = strtok (NULL, ",")) {
+ p = range;
+ while (*p != '\0' && isdigit (*p))
+ p ++;
+ if (*p == '\0') { /* single rank */
+ if (rank == atoi (range)) {
+ *offset = passed;
+ return 1;
+ }
+ passed ++;
+
+ } else if (*p == '-') { /* lower-upper */
+ upper = ++ p;
+ while (isdigit (*p))
+ p ++;
+ if (*p != '\0') {
+ error ("Invalid task range specification (%s) "
+ "ignored.", range);
+ continue;
+ };
+ low_num = atoi (range);
+ high_num = atoi (upper);
+ if ((rank >= low_num) && (rank <= high_num)) {
+ *offset = passed + (rank - low_num);
+ return 1;
+ } else
+ passed += (1 + high_num - low_num);
+
+ } else {
+ error ("Invalid task range specification (%s) ignored.",
+ range);
+ }
+ }
+ return 0;
+}
+
+/* substitute "%t" or "%o" in argument with task number or range offset */
+static void
+_sub_expression(char *args_spec, int task_rank, int task_offset)
+{
+ char tmp[BUF_SIZE];
+
+ if (args_spec[1] == 't') {
+ /* task rank */
+ strcpy(tmp, &args_spec[2]);
+ sprintf(args_spec, "%d%s", task_rank, tmp);
+
+ } else if (args_spec[1] == 'o') {
+ /* task offset */
+ strcpy(tmp, &args_spec[2]);
+ sprintf(args_spec, "%d%s", task_offset, tmp);
+ }
+}
+
+/* Return this tasks rank from environment variable,
+ * Use SLURM_PROCID if available, otherwise use PMI_RANK */
+static int
+_get_rank(char **prog_env)
+{
+ int i, pmi_rank = 0;
+
+ for (i=0; ; i++) {
+ if (prog_env[i] == NULL)
+ break;
+ if (strncmp(prog_env[i], "SLURM_PROCID=", 13) == 0)
+ return atoi(&prog_env[i][13]);
+ if (strncmp(prog_env[i], "PMI_RANK=", 9) == 0)
+ pmi_rank = atoi(&prog_env[i][9]);
+ }
+ if (pmi_rank)
+ return pmi_rank;
+
+ error("Task rank unknown.");
+ return -1;
+}
+
+/* Given a program name, translate it to a fully qualified pathname
+ * as needed based upon the PATH environment variable */
+static char *
+_build_path(char* fname, char **prog_env)
+{
+ int i;
+ char *path_env = NULL, *dir;
+ static char file_name[256], file_path[256]; /* return values */
+ struct stat buf;
+
+ /* make copy of file name (end at white space) */
+ snprintf(file_name, sizeof(file_name), "%s", fname);
+ for (i=0; i<sizeof(file_name); i++) {
+ if (file_name[i] == '\0')
+ break;
+ if (!isspace(file_name[i]))
+ continue;
+ file_name[i] = '\0';
+ break;
+ }
+
+ /* check if already absolute path */
+ if (file_name[0] == '/')
+ return file_name;
+
+ /* search for the file using PATH environment variable */
+ for (i=0; ; i++) {
+ if (prog_env[i] == NULL)
+ return file_name;
+ if (strncmp(prog_env[i], "PATH=", 5))
+ continue;
+ path_env = xstrdup(&prog_env[i][5]);
+ break;
+ }
+
+ dir = strtok(path_env, ":");
+ while (dir) {
+ snprintf(file_path, sizeof(file_path), "%s/%s", dir, file_name);
+ if (stat(file_path, &buf) == 0)
+ break;
+ dir = strtok(NULL, ":");
+ }
+ if (dir == NULL) /* not found */
+ snprintf(file_path, sizeof(file_path), "%s", file_name);
+
+ xfree(path_env);
+ return file_path;
+}
+
+extern int
+task_exec(char *fname, char **prog_env)
+{
+ FILE* conf_file;
+ char line[BUF_SIZE];
+ int line_num = 0;
+ int task_rank, task_offset;
+ char* p, *s;
+ char* rank_spec, *prog_spec, *args_spec;
+ int prog_argc;
+ char* prog_argv[(BUF_SIZE - 4)/ 2];
+
+ task_rank = _get_rank(prog_env);
+ if (task_rank < 0)
+ return -1;
+
+ conf_file = fopen (fname, "r");
+ if (conf_file == NULL) {
+ error("Unable to open config_file \"%s\": %m", fname);
+ return -1;
+ }
+
+ while (fgets (line, BUF_SIZE, conf_file) != NULL) {
+ line_num ++;
+ if (strlen (line) >= (BUF_SIZE - 1)) {
+ error ("Line %d of configuration file %s too long",
+ line_num, fname);
+ fclose (conf_file);
+ exit (-1);
+ }
+
+ p = line;
+ while (*p != '\0' && isspace (*p)) /* remove leading spaces */
+ p ++;
+
+ if (*p == '#') /* only whole-line comments handled */
+ continue;
+
+ if (*p == '\0') /* blank line ignored */
+ continue;
+
+ rank_spec = p;
+
+ while (*p != '\0' && !isspace (*p))
+ p ++;
+ if (*p == '\0') {
+ error("Invalid configuration line: %s", line);
+ return -1;
+ }
+ *p ++ = '\0';
+
+ if (!_in_range (task_rank, rank_spec, &task_offset))
+ continue;
+
+ while(*p != '\0' && isspace (*p))
+ p ++;
+ prog_spec = _build_path(p, prog_env);
+
+ if (prog_spec[0] == '\0') {
+ error("Program for task rank %d not specified.",
+ task_rank);
+ return -1;
+ }
+
+ while (*p != '\0' && !isspace (*p))
+ p ++;
+ *p ++ = '\0';
+
+ while (*p != '\0' && isspace (*p))
+ p ++;
+ args_spec = p;
+
+ prog_argv[0] = prog_spec;
+ prog_argc = 1;
+ while (*args_spec != '\0') {
+ /* Only simple quote and escape supported */
+ prog_argv[prog_argc ++] = args_spec;
+ CONT: while (*args_spec != '\0' && *args_spec != '\\'
+ && *args_spec != '%'
+ && *args_spec != '\'' && !isspace (*args_spec)) {
+ args_spec ++;
+ }
+ if (*args_spec == '\0') {
+ /* the last argument */
+ break;
+
+ } else if (*args_spec == '%') {
+ _sub_expression(args_spec, task_rank,
+ task_offset);
+ args_spec ++;
+ goto CONT;
+
+ } else if (*args_spec == '\\') {
+ /* escape, just remove the backslash */
+ s = args_spec ++;
+ p = args_spec;
+ do {
+ *s ++ = *p;
+ } while (*p ++ != '\0');
+ goto CONT;
+
+ } else if (*args_spec == '\'') {
+ /* single quote,
+ * preserve all characters quoted. */
+ p = args_spec + 1;
+ while (*p != '\0' && *p != '\'') {
+ /* remove quote */
+ *args_spec ++ = *p ++;
+ }
+ if (*p == '\0') {
+ /* closing quote not found */
+ error("Program arguments specification"
+ " format invalid: %s.",
+ prog_argv[prog_argc -1]);
+ return -1;
+ }
+ p ++; /* skip closing quote */
+ s = args_spec;
+ do {
+ *s ++ = *p;
+ } while (*p ++ != '\0');
+ goto CONT;
+
+ } else {
+ /* space */
+ *args_spec ++ = '\0';
+ while (*args_spec != '\0'
+ && isspace (*args_spec))
+ args_spec ++;
+ }
+ }
+
+ prog_argv[prog_argc] = NULL;
+ if (execve (prog_spec, prog_argv, prog_env) == -1) {
+ error("Error executing program \"%s\": %m", prog_spec);
+ return -1;
+ }
+ }
+
+ fclose (conf_file);
+ error("Program for task rank %d not specified.", task_rank);
+ return -1;
+}
diff --git a/src/slurmd/slurmstepd/task_exec.h b/src/slurmd/slurmstepd/task_exec.h
new file mode 100644
index 0000000000000000000000000000000000000000..d6b953abfc73cd8a9bbbfd1e1863b5d60060eb65
--- /dev/null
+++ b/src/slurmd/slurmstepd/task_exec.h
@@ -0,0 +1,32 @@
+/*****************************************************************************\
+ * src/slurmd/slurmstepd/task_exec.h - Task specific exec
+ *****************************************************************************
+ * Copyright (C) 2006 The Regents of the University of California.
+ * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ * Written by Morris Jette <jette1@llnl.gov>.
+ * UCRL-CODE-217948.
+ *
+ * This file is part of SLURM, a resource management program.
+ * For details, see <http://www.llnl.gov/linux/slurm/>.
+ *
+ * SLURM is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * SLURM is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with SLURM; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+\*****************************************************************************/
+
+#ifndef _SLURMD_TASK_EXEC_H
+#define _SLURMD_TASK_EXEC_H
+
+extern int task_exec(char *fname, char **prog_env);
+
+#endif /* !_SLURMD_TASK_EXEC_H */